Narrowboat in the context of "Birmingham Canal Navigations"

The head of navigation is the farthest point above the mouth of a river that can be navigated by ships. Determining the head of navigation can be subjective on many streams, as the point may vary greatly with the size or the draft of the ship being contemplated for navigation and the seasonal water level. On others, it is quite objective, being caused by a waterfall, a low bridge that is not a drawbridge, or a dam without navigation locks. Several rivers in a region may have their heads of navigation along a line called the fall line.

Longer rivers such as the River Thames may have several heads of navigation depending on the size of the vessel. In the case of the Thames, that includes London Bridge, which historically served as the head of navigation for tall ships; Osney Bridge in Oxford, which has the lowest headroom of any bridge on the Thames that generally restricts navigation to smaller vessels such as narrowboats and cabin cruisers, and the long reach above St John's Lock, the first lock downstream of the river’s source, on the outskirts of Lechlade, where the river can become treacherously narrow and shallow for anything but small motorboats and human-powered vessels.

Chirk Tunnel is a canal tunnel near Chirk, Wales. It lies on the Llangollen Canal, immediately northwards of the Chirk Aqueduct. It is 421 metres (460 yd) long and has a complete towpath inside.

The tunnel is designed for a single standard narrowboat, so passing is not possible. The tunnel is straight enough to be able to see if a boat is already inside the tunnel, and boats are required to show a light. Northbound boats must maintain power and momentum in order to push through, due to the shallow, narrow nature of the canal in the tunnel (such that water has little space to pass around the displacement of the boat), and the relatively fast 2 miles per hour (3.2 km/h) southbound current of the canal. The tunnel, the tunnel portals and the canal basin are collectively a Grade II* listed structure.

The Pontcysyllte Aqueduct (Welsh pronunciation: [ˌpɔntkəˈsəɬtɛ]; Welsh: Traphont Ddŵr Pontcysyllte) is a navigable aqueduct that carries the Llangollen Canal across the River Dee in the Vale of Llangollen in northeast Wales.

The 19-arched stone and cast iron structure is for use by narrowboats and was completed in 1805 having taken ten years to design and build. It is 12 feet (3.7 metres) wide and is the longest aqueduct in Great Britain as well as the highest canal aqueduct in the world. A towpath runs alongside the watercourse on one side.

Navigable aqueducts (sometimes called navigable water bridges or canal bridges) are bridge structures that carry navigable waterway canals over other rivers, valleys, railways or roads. They are primarily distinguished by their size, carrying a larger cross-section of water than most water-supply aqueducts. Roman aqueducts were used to transport water and were created in ancient Rome. The 662-metre (2,172 ft) long steel Briare aqueduct carrying the Canal latéral à la Loire over the River Loire was built in 1896. It was ranked as the longest navigable aqueduct in the world for more than a century, until the Magdeburg Water Bridge in Germany took the title in the early 21st century.

Early aqueducts such as the three on the Canal du Midi had stone or brick arches, the longest span being 18.3 metres (60 ft) on the Cesse Aqueduct, built in 1690. But, the weight of the construction to support the trough with the clay or other lining to make it waterproof made these structures clumsy. In 1796 Longdon-on-Tern Aqueduct, the first large cast iron aqueduct was built by Thomas Telford at Longdon-on-Tern on the Shrewsbury Canal. It has a total length of 57 metres (187 ft) across three intermediate piers. Within ten years Telford had completed the far more ambitious Pontcysyllte Aqueduct in Wales on the Llangollen Canal over the River Dee valley, with a total length 307 metres and a height of 38 metres, making it the tallest navigable aqueduct in the world. Other cast-iron aqueducts followed, such as the single-span Stanley Ferry Aqueduct on the Calder and Hebble Navigation in 1839, with its innovative 50-metre (160 ft) through arch design.

A marina (from Spanish [maˈɾina], Portuguese [mɐˈɾinɐ] and Italian [maˈriːna]: "related to the sea") is a dock or basin with moorings and supplies for yachts and small boats.A marina differs from a port in that a marina does not handle large passenger ships or cargo from freighters.

The word marina may also refer to an inland wharf on a river or canal that is used exclusively by non-industrial pleasure craft such as canal narrowboats.

The caisson lock is a type of canal lock in which a narrowboat is floated into a sealed watertight box and raised or lowered between two different canal water levels. It was invented in the late 18th century as a solution to the problem posed by the excessive demand for water when conventional locks were used to raise and lower canal boats through large height differences. Such locks, each of which would only raise and lower boats through small height differences of a few feet, would not suffice when large height differences had to be tackled nor when water was in short supply. The caisson (or caisoon) was thought to be one solution, although it transpired that the technology of the day was not capable of achieving this type of construction economically.

It was designed primarily as a water-saving measure, and also was an attempt to minimise construction costs compared with other engineering solutions of the time. In use, it was capable of replacing up to seven conventional locks. Another benefit was increased speed of boat descent/ascent.

The Barton Swing Aqueduct is a moveable navigable aqueduct in Barton upon Irwell, Greater Manchester, England. It carries the Bridgewater Canal across the Manchester Ship Canal. The swinging action allows large vessels using the ship canal to pass through and smaller craft, both narrowboats and broad-beam barges, to cross over the top. The aqueduct, the first and only swing aqueduct in the world, is a Grade II* listed building, and considered a major feat of Victorian civil engineering. Designed by Sir Edward Leader Williams and built by Andrew Handyside and Company of Derby, the swing bridge opened in 1894 and remains in regular use.

The Dudley Canal is a canal passing through Dudley in the West Midlands of England. The canal is part of the English and Welsh network of connected navigable inland waterways and forms part of the popular Stourport Ring narrowboat cruising route.

The first short section, which connected to the Stourbridge Canal, opened in 1779. This was then connected to the Birmingham Canal system in 1792 via Dudley Tunnel. Almost immediately, work started on an extension, called Line No. 2, which ran through another long tunnel at Lapal to reach the Worcester and Birmingham Canal. This was completed in 1798 but significant trade had to wait until the Worcester and Birmingham was completed in 1802. In 1846, the company amalgamated with the Birmingham Canal Navigations and various improvements followed including the Netherton Tunnel. This was of a similar length to and parallel to the Dudley Tunnel but it was much bigger with towpaths on both sides and gas lighting. It was the last canal tunnel built in England.